Black azo dye.



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MARTIN HERZBERG, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBEN- FABRIKEN OF ELBERFELD 00., OF NEW YORK, N. Y., A CORPORATION OF NEWV YORK.

BLACK Azo ore.

Specification of Letters Patent.

Patented Aug. 22, 1905.

Application filed May 29, 1905. $eria1No. 262,905.

I have found that new and valuable azo dyestuffs are obtained by first combining the diazo compounds obtainable from mononitroacetyl paraphenylenediamin having the formula with alkyloxynaphthol disulfonic acids and then splitting off from the resulting dyestuffs the acteyl group by saponification.

The new d yestuifs are in the shape of their alkaline salts dark powders soluble in water. They yield upon suitable treatment with stannous chlorid and hydrochloric acid triamidobenzene and amidoalkyloxynaphthol di sulfonic acids and dye unmordanted wool from acid-baths black shades.

In carrying out my process practically I can proceed as follows, the parts being by weight: 19.5 .parts of mononitroacetyl-paraphenylenediamin having the above-given for mula are diazotized in the usual manner by means of hydrochloric acid and seven parts of sodium nitrite, and the resulting diazo compound is added to a solution of thirtyfive parts of 1-ethoxy-8-naphthol-3.6-disulfonic acid. After some time sodium acetate is added, and it is then stirred until the formation of the dyestu'lf be completed. l/V hen this point is reached, the dyestufl is precipitated by the addition of common salt, filtered off, and dried. It dyes Wool from acid-baths violet-red shades. The coloring-matter thus obtained is then heated to boiling with eight times its quantity of a [ifty-per-cent. sulfuric acid in order to eliminate the acetyl group. The new azo dyestufi' thus produced deposits during the heating in a crystalline shape.

The isolation of the intermediate product is not necessary. The acetyl group can also be split off by directly boiling the reaction mass with an acid or an alkali.

The new dyestufi thus obtained is in the shape of its sodium salt a black powder soluble in water with a violet color and soluble in concentrated sulfuric acid of 66 Baum with a greenish-blue color, which is changed into red by the addition of ice. It yields upon reduction with stannous chlorid and hydrochloric acid tlltll'lidObODZOllG and l-oxy-Q- amido 8 ethoxy naphthalene 8-6-disulfonic acid and dyes unmordanted wool reddish-black shades.

The process proceeds in an analogous manner on using other alkyloxynaphthol disulfonic acids, such as 1-alkyloxy-S-naphthol-2.4L- disulfonie acid, 1-alkyloxy-5-naphthol-3.T-disulfonic acid, or the like.

Having now described my invention and in what manner. the same is to be performed, what I claim as new, and desire to secure by Letters Patent, is-

1. The herein-described new azo dyestuffs obtainable by first combining the diazo con1- pound of n1ononitroacetyl-paraphcnylenediamin having the above-given formula with alkyloxynaphthol disulfonic acids and then splitting off the acetyl group by saponilieation, which dyestuffs are in the shape of their all aline salts dark powders soluble in water; dyeing unmordanted wool black shades; and yielding upon reduction with stannous chlorid and hydrochloric acid triamidobenzene and amidoalkyloxynaphthol disulfonic acids, substantially as hereinbefore described.

2. The herein-described new dyestufl obtainable by first combining the diazo compound of mononitroacetyl--paraphenylenediamin having the above-given formula with 1- ethony- 8-naphthol -3.6 disulfonic acid and then splitting off the acetyl group by saponilication, which dyestuif is in the shape of its sodium salt a dark powder soluble in water with a violet color; being dissolved by concentrated sulfuric acid of 66" liaume with a greenish-blue color which is clumged into red by the addition of ice; dyeing unmordanted wool reddish-black shades; and yielding upon reduction with stannous chlorid and hydrochloric acid triamir'lobenzene and Lexy-2- amido 8 ethoxynaphthalene 2). 6 disulfonic acid, substantially as hereinbefore described.

In testimony whereof I have sigi led my name in the presence of two subscribing witnesses.

ft IAlt'llN HERZBERG.

Witnesses:

O'r'ro lG'iNm, J. A. .RIITIYIPERSUAUS. 

